Ferrari Power Unit Hardware & Software

[PlatinumZealot]

Special qualy fuel is also forbidden by the rules as far as I'm aware...

I think two fuels are allowed.

[3jawchuck]

Special qualy fuel is also forbidden by the rules as far as I'm aware...

I think two fuels are allowed.

Relevant parts of the regs I guess.

19.7 Fuel approval :
19.7.1 Before any fuel may be used in an Event, two separate five litre samples, in suitable
containers, must be submitted to the FIA for analysis and approval.
19.7.2 No fuel may be used in an Event without prior written approval of the FIA.
19.7.3 No competitor may have more than five fuel formulations approved for use during a
Championship season.
19.7.4 No competitor may have more than two approved fuels available during an Event

[gruntguru]

I think 400 bar peak cylinder pressure is a bit unrealistic. Maybe with moderate detonation.

400 is very high but it does agree with a statement from Mercedes last year (elephants on pistons) which suggested 400+ bar.

The v8 had 13-14 CR and that was a geometrical limitation. I don t see how you can get 16 without reducing valve lift considerably or designing a piston with massive recesses.

B/S ratio is currently ~1.5 compared to ~2.5 for the V8s.

Apart from that, engines making peak power at 11k rpm don't need as much valve area and lift per unit displacement as those making peak power at 17 or 18k rpm.

[wuzak]

I still think honeycomb structures are rubbish at dissipating heat. Unless you fill in the gaps with a more conductive material (which is not allowed).

I thought the idea was to maximise the heat in the combustion chamber to create power in the expansion stroke or in expansion through the turbine.

Dissipating heat through the piston to the cylinder walls, oil or the air in the crankcase seems like something to be avoided if possible.

[PlatinumZealot]

I guess there is an acceptable heat loss. Without it, the surface temperatures would be ridiculously high and all manner of things will go down. Huge expansion, surface cracks, surface oxidation, hot spots. So, some amount of heat dissipation is necessary. It's not like gas turbine where you have basically motion in one direction and very predictable and consistent gas flow over the blades so that you cool with steady stream steam/air or whatever. Pistons hammering up and down, cool air, hot hair, fuel, explosions.. it's chaos inside of a piston engine.

[wuzak]

But isn't that the reason for running steel pistons? They can cope with higher temperatures.

[J.A.W.]

I think 400 bar peak cylinder pressure is a bit unrealistic. Maybe with moderate detonation.

400 is very high but it does agree with a statement from Mercedes last year (elephants on pistons) which suggested 400+ bar.

The v8 had 13-14 CR and that was a geometrical limitation. I don t see how you can get 16 without reducing valve lift considerably or designing a piston with massive recesses.

B/S ratio is currently ~1.5 compared to ~2.5 for the V8s.

Apart from that, engines making peak power at 11k rpm don't need as much valve area and lift per unit displacement as those making peak power at 17 or 18k rpm.

& especially with 'turbo-boost' - being pumped in, @ several times ambient-N/A's best volumetric levels..

[henry]

I still think honeycomb structures are rubbish at dissipating heat. Unless you fill in the gaps with a more conductive material (which is not allowed).

I thought the idea was to maximise the heat in the combustion chamber to create power in the expansion stroke or in expansion through the turbine.

Dissipating heat through the piston to the cylinder walls, oil or the air in the crankcase seems like something to be avoided if possible.

I'm guessing to maximise the average temperature in the cylinder you need to minimise the peak temperatures, the hot spots. Perhaps a "honeycomb" structure could be used to micromanage the heat flows in the piston reducing the hot spots, increasing the average temperature and doing so with limited weight penalty.

[kalinka]

Special qualy fuel is also forbidden by the rules as far as I'm aware...

I think two fuels are allowed.

Relevant parts of the regs I guess.

19.7 Fuel approval :
19.7.4 No competitor may have more than two approved fuels available during an Event

Wow ! I didn't knew that..I've heard no comments from any TV commentator or expert regarding qualy fuels. Do they just think it has no meaningful effect, or just plain lack of knowledge ? Do we know from a reliable source that they are indeed using this rule to have a separate qualy fuel mix ? Sorry, it's a becoming OT now.

[Holm86]

I still think honeycomb structures are rubbish at dissipating heat. Unless you fill in the gaps with a more conductive material (which is not allowed).

I thought the idea was to maximise the heat in the combustion chamber to create power in the expansion stroke or in expansion through the turbine.

Dissipating heat through the piston to the cylinder walls, oil or the air in the crankcase seems like something to be avoided if possible.

I'm guessing to maximise the average temperature in the cylinder you need to minimise the peak temperatures, the hot spots. Perhaps a "honeycomb" structure could be used to micromanage the heat flows in the piston reducing the hot spots, increasing the average temperature and doing so with limited weight penalty.

An enclosed honeycomb structure will work as an insulator, so its no good at dissapating heat. Unless it would be an open structure which oil was sprayed onto, but structually i can't see how that would work.

[J.A.W.]

Honeycomb structures for heat control have been understood/utilized - for over 1/2 a century..
See below:
www.nationalmuseum.af.mil/Portals/7/doc ... n_plan.pdf

[Tommy Cookers]

structurally it would work roughly as would using T section joists holding up a floor in a building
not as well as the usual (imagine here a Roman I) I section joists
but much better than the same weight of metal in the form of a conventional crown (notionally a constant thickness plate)
steel being 3x the density (of al alloy) the required strength if from conventional form will likely be too heavy
(a 6mm al alloy plate is the same weight as a 2mm steel plate but much stronger in this use)

we need a controlled drain of heat to lubricant-as-coolant just as we drain heat elsewhere to coolant-as-coolant
ie an piston structure open on the underside as Holm has said
controlled to prevent excess piston crown temperature and consequent detonation or other disadvantage

[outsid3r]

structurally it would work roughly as would using T section joists holding up a floor in a building
ie much better than the same amount of metal in the form of a notionally constant thickness (plate)

we need a controlled drain of heat to lubricant-as-coolant just as we drain heat elsewhere to coolant-as-coolant
ie an piston structure open on the underside as Holm has said
controlled to prevent excess piston crown temperature and consequent detonation or unsuitable behaviour

But wasn't this update supposed to be a revolutionary thing Ferrari did using 3D printing technology? I know I've heard this before in more than one article... An open honeycomb structure can be done using (relatively) low-tech CNC machinery and would have probably been looked at by several other engine technicians before. So I'm still wondering if they are trying to invent something cleverer than this...

What about a closed honeycomb structure pre-filled with oil and maybe very very tiny holes/slits in each compartment (through which oil will likely not escape) just for legality's sake

[63l8qrrfy6]

I think 400 bar peak cylinder pressure is a bit unrealistic. Maybe with moderate detonation.

400 is very high but it does agree with a statement from Mercedes last year (elephants on pistons) which suggested 400+ bar.

The v8 had 13-14 CR and that was a geometrical limitation. I don t see how you can get 16 without reducing valve lift considerably or designing a piston with massive recesses.

B/S ratio is currently ~1.5 compared to ~2.5 for the V8s.

Apart from that, engines making peak power at 11k rpm don't need as much valve area and lift per unit displacement as those making peak power at 17 or 18k rpm.

I remember looking into the elephants claim and I think it gives something like 350 bar +/- 100 depending on the species and gender of elephant.

Shouldn t the smaller B/S drive higher lift to achieve equivalent vale curtain area thus making higher compression ratios even harder to get?

[63l8qrrfy6]

I still think honeycomb structures are rubbish at dissipating heat. Unless you fill in the gaps with a more conductive material (which is not allowed).

I thought the idea was to maximise the heat in the combustion chamber to create power in the expansion stroke or in expansion through the turbine.

Dissipating heat through the piston to the cylinder walls, oil or the air in the crankcase seems like something to be avoided if possible.

In addition to what PZ said, steel is a very good insulator compared to Al. I think just by swapping to steel you would decrease heat rejection to oil. The downside is that this makes it very hard to control crown temperatures for durability reasons.